diff -ruN libslang2.bak/Makefile libslang2/Makefile
--- libslang2.bak/Makefile	2018-06-18 23:35:10.155295000 +0300
+++ libslang2/Makefile	2018-06-18 23:37:06.907600000 +0300
@@ -13,13 +13,14 @@
 
 CONFLICTS=	libslang-1.*.j[0-9]
 
-USES=		tar:bzip2
+USES=		ncurses tar:bzip2
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
 MAKE_JOBS_UNSAFE=	yes
 PLIST_SUB+=	SHLIB_VERSION=${PORTVERSION}
 
 CONFIGURE_ARGS+=--with-pkgconfigdir=${PREFIX}/libdata/pkgconfig
+LDFLAGS+=	-lncurses
 
 ALL_TARGET=	all static
 INSTALL_TARGET=	install install-static